The disinfection of wastewater is the process of selective destruction of disease-causing micro-organisms contained therein. This is distinguishable from sterilization, for example, which is the destruction of all micro-organisms. In wastewater treatment, the three categories of micro-organisms of greatest concern are disease-causing bacteria, bacterial viruses, and amoebic cysts. Diseases which may be caused by water-borne bacteria include typhoid, cholera, paratyphoid, and bacillary dysentery. Diseases which may be caused by water-borne viruses include poliomyelitis and infectious hepatitis.
There are many known techniques for disinfecting wastewater, including the use of chemical or physical agents, mechanical means, and ultra-violet radiation. Of these, the traditional method of disinfection has been the use of chemical agents in the form of chlorine. Chlorine usage has numerous drawbacks, however, including the fact that it is expensive and may pollute effluent water with undesirable by-products.
There are numerous disinfection systems which utilize ultra-violet radiation to disinfect wastewater. For example, U.S. Pat. No. 3,637,342 discloses an ultra-violet fluid sterilizer; U.S. Pat. No. 3,924,139 discloses a photo-oxidation apparatus utilizing oxidizing agents in combination with ultra-violet radiation; U.S. Pat. No. 4,103,167 discloses an ultra-violet liquid purification system; U.S. Pat. No. 4,204,956 discloses a water purification system utilizing ultra-violet radiation. The following U.S. Pat. Nos. 4,400,270, 4,471,225, 4,621,195, 4,676,896, and 4,909,931, also disclose ultra-violet disinfection apparatus.
In light of current environmental regulations relating to the quality of the effluent discharged from wastewater treatment systems, it is imperative that wastewater treatment systems provide consistent, highly effective disinfection of wastewater. The system of the present invention accomplishes that objective.